This invention pertains to the art of methods and apparatuses for filtering particles from a fluid, and more specifically to methods and apparatuses for oil filter enhancements and for filtering magnetically attractable particles and other suspended particles in an engine lubricant using magnets or other filter media.
Much of the fine abrasive particles produced inside an internal combustion engine at the site of friction is carried immediately away by the flow of lubricating fluid. A major part of an engine wear is due to the destructive nature of small ferrous abrasive particles being recycled continuously to the friction bearing surfaces by the engine""s lubrication system. This is due to the limited ability of the normally provided oil filter medium to arrest such abrasive particles. By design, the filter has to allow for a relatively unrestricted normal oil flow, this can only happen with relatively large pore sizes. Most filter media are designed to stop particles of about 20 microns cross-sectional dimension. A lot of magnetic particles in the range of sub-micronic to 20 microns cross-sectional dimension are produced and generally not arrested by the media, or even dangerously bypassed during cold engine starts and/or partially clogged and saturated filter media conditions. Therefore, if these particles are not removed, they continue to produce ever more metal shavings in an increasing and uncontrolled avalanche effect that may lead, according to many experts, to substantial engine wear. To further complicate this scenario, current engines and like machinery are designed with tighter tolerances, higher running temperatures, continuously increasing performance demands, extended service intervals, longer powertrain warranties, and more stringent smog specifications. This wear scenario eventually results in a degradation of close tolerances at critical locations between rotating parts, causing a loss of performance, more frequent maintenance repairs, and eventually catastrophic engine failure. It is therefore of great interest that a convenient, non-intrusive method and apparatus be introduced to address at least one of the major causes of engine performance decay, premature engine wear, and premature disposal of the lubricating oil.
Attempts to enhance the filtration capabilities of filters have been tried by means of creating a magnetic field in order to attract magnetic particles to the internal wall of the common disposable spin on filter. This is generally attempted by placing magnets in different arrangements around the outside surface of a spin on filter. However these previous known structures provide limited, incomplete, weak, statistically insignificant, expensive, hard to remove, bulky, and generally their effectiveness is limited to very small areas of the canister filter inside wall. Even with the approach of U.S. Pat. No. 5,647,993 issued to Karp, suggesting a helical arrangement to capture the magnetic field around the outside wall of the filter, the net effect on the internal wall of the filter becomes negligible to effectively arrest magnetic particles. When fast lubricant flow, turbulence, magnetic particle cluster separation, low statistical contact of same volume in proximity to weakly magnetized areas are considered, this approach sounds effective but the results have proven generally unsatisfactory.
The art of placing magnets on the external wall of a filter is inherently flawed for two mutually exclusive reasons: weak magnets can only exert weak attractive fields on the internal surface of the spin-on filter, and are therefore largely ineffective to attract and retain magnetic particles. This is due to fluid turbulence, weak magnetic influence, fast flow, localized eddy currents, magnetic leakage, and limited enhanced area. On the other hand, as magnet size, number, and strength increases, other problems arise such as more expensive, bulky, and hard to remove.
Other problems involve the choice of materials to withstand the high temperatures associated with the working lubricant, which may reach up to 300 degrees Farenheit in rare occasions. For example U.S. Pat. No. 5,441,647, issued to Wascher, discusses a material having a higher melting point than the operating fluid, or the similar approach of a suction cup with magnet as shown in U.S. Pat. No. 5,571,411, issued to Butler et al.
Other problems of magnets attached to the canister filter include the difficulty of removal of the magnets, the limited clearance in the radial direction from the canister once the filter is installed, the variability in the canister filter diameter, the discipline required every time to remove and place on the new filter canister. In some cases, as suggested in U.S. Pat. No. 5,282,963, issued to Hull et al., a tool is needed to remove the apparatus. In addition, the use of magnetic material clamps tend to weaken the already weak effect through the canister wall of the magnets it intends to hold. In some vibration environments, the devices may detach themselves, causing immediate possible damage due to sudden cluster separation inside the filter upon loss of retaining magnetic field, resulting in the sudden and concentrated release of all collected particle clusters.
Yet another problem, demonstrating the lack of commercial success of the current art, is the cost and discipline in removing and replacing, which may not justify in terms of quantifiable evidence, the economic benefit of using them. Therefore, any cost and inconvenience factor must be minimized or eliminated to overcome this problem.
In some prior art, such as U.S. Pat. No. 4,450,075 issued to Krow, the magnets are in direct contact with the lubricating fluid. This is an improvement over the magnets attached to the walls, because all the surface area and magnetic strength of the magnets are exposed directly to the fluid. However, placing the magnets in the highly turbulent and fast flow areas of the oil canister center, or other similar locations, pose an additional risk of clogging the flow. In some situations, due to the reduction of flow area, this create areas of higher than normal turbulence and velocity, according to flow and mass continuity theory equations. These conditions result in an even higher risk, not only to counteract the attraction and retention of the particles, but an easier dislodging of already built particulate clusters, if any.
In some situations, a complicated arrangement such as an external bypass oil filter and adapter arrangement may be used to remove magnetic and non-magnetic particulate. These obviously complement the filtering function of the normal full flow filter, but at the expense of high cost and space sacrifice in an already cramped engine bay. In addition, as much as 10% of oil flow may be diverted away from the intended regions for oil protection, and in some high temperature operating cases, this may mean heat stress through oil cooling reduction flow to bearing surfaces. Such a system is shown in U.S. Pat. No. 4,406,784 issued to Cochran, which requires extensive external hardware and installation cost.
Many patents teach different and incomplete ways about the removal of magnetic particles from a fast flowing lubricating fluid, and in some cases from the lubricant at rest, such as in the case of magnetic bolts shown in U.S. Pat. No. 5,465,078 issued to Jones. Approaches to removing magnetic particles from the flow of internal combustion engine lubricant tend to be of the following descriptors: external magnets using the magnetic external wall of the filter, immersed in the path of turbulent and fast oil flow, different means of installing and removing from canister, complicated and expensive to install apparatus, helical configurations for magnetic fields, external by-pass filtration, elaborate and expensive filters, etc. From those descriptors the following US Patents are examples of this prior art: U.S. Pat. Nos. 4,026,805, Fowler; 4,051,036, Conrad et al.; 4,052,312, King; 4,053,409, Kuhfuss; 4,218,320, Liaw; 4,265,748, Villani et al.; 4,406,784, Cochran; 4,446,019, Robinson; 4,450,075, Krow; 4,498,987, Inaba; 4,529,517, Bertil; 4,561,395, McMullen; 4,585,553, Hikosaka et al.; 4,592,836, Chiao; 4,629,558, Garrity; 4,689,144, Holmes; 4,700,670, Schade; 4,705,626, Morelli; 4,763,092, Tomita; 4,826,592, Taylor; 4,894,153, Shirdavant; 4,992.166, Lowsky et al.; 5,000,779, Hebert; 5,039,406, Whittington; 5,078,871, McCready; 5,089,129, Brigman; 5,186,827, Liberti et al.; 5,228,990, Chiang; 5,273,648, Caiozza; 5,282,963, Hull et al.; 5,354,462, Pertt; 5,441,647, Wascher et al.; 5,465,078, Jones; 5,468,381, Williamson; 5,556,540, Brunstig; 5,569,373, Smith et al.; 5,571,411, Butler et al.; 5,634,755, Jones; 5,647,993, Karp; 5,695,637, Jiang et al; 5,702,598, Lemon et al.; 5,817,233, Cooper, 5,830,371, Smith; 5,885,447, Theisen et al., among others.
Although these and other devices have attempted to remove magnetic particles from the engine oil flowing through an engine lubrication circuit, they have collectively failed to address the desired simultaneous effectiveness-cost-convenience conditions.
In view of the foregoing disadvantages inherent in the known types of magnetic belt apparatus, bypass filtration, internally disposed magnets, and other similar approaches found in the prior art, the present invention provides the very objective of removing and retaining magnetic particles suspended in the working fluid in a conduit, in a novel and most effective manner. As such, the purpose of the present invention, which will be described in greater detail, is to provide an apparatus that delivers the functions seeked by the prior art, but with all the advantages and none of the disadvantages and shortcomings of prior art.
The present invention takes advantage of a combination of factors not suggested by prior art. The present invention does not reside on any of those factors per se, but rather in the suggested combination of them herein disclosed and claimed. In order to remove and retain particles suspended in a moving fluid, the following combined conditions suggest a method and an apparatus:
1. Effect a pressure differential by placing a lubricant flow restriction means in the flow path;
2. provide a means to channel an amount of lubricant fluid through a bypass duct;
3. slow down the bypassed lubricant flow to effect successful and consistent entrapment and retention of the suspended particles;
4. pass the bypass lubricant flow through a filter medium or expose the flow directly to a magnet surface to avoid magnetic leakage and field weakening, thus maximizing magnet utilization, effectiveness, and value;
5. promote turbulence of the bypass flow to enhance particle capture and to minimize particle cluster separation;
6. maximize the poles and magnet surface exposed directly to the bypass lubricant flow to minimize particle cluster separation by maximizing trapped volume capability while minimizing cluster thickness, i.e.: Exposed magnet area (Maximized) X Cluster thickness (Minimized)=Retained cluster volume (Maximized at minimum thickness); maximize magnet poles and area exposed to lubricant flow to maximize cluster retention volume, thereby maximizing or eliminating cleaning maintenance intervals;
7. utilize the relatively abundant clearance provided along the longitudinal axis of present filters as a design advantage;
8. use the diameter commonality of filter base plates as a design advantage to facilitate one-size-fit-all installation, convenience, and lower cost;
9. use symmetry in the design to further lower the number of parts needed and therefore the cost;
10. use known geometry of engine design to produce a product that can be installed in a few minutes without using special tools nor expensive and time consuming engine modifications;
11. utilize the device as a liquid to air cooler with the addition of a set of cooling fins around the filter body to remove heat from the bypass flow;
12. minimize space utilization in an already cramped automotive engine bay by providing a small device.
The present invention solves the problems encountered in prior art with an apparatus that delivers the function of magnetic and other particle removal in a new and novel manner. In an automobile, the device is interposed between the normally provided spin on oil filter and its point of attachment to the engine block. The device is similar in size and shape to a hockey puck, substantially a flat cylinder. It has an internal chamber or duct filled with numerous discrete magnets, a ring magnet with multiple poles, a magnetic grid or sponge, or other filter media. The puck is designed with a number of radially disposed holes which allow the pressurized lubricant fluid coming from the normally provided engine oil pump to pass through the puck and into the filter. This is the main flow. However, the radially disposed holes collectively act as an orifice restriction to the flow of oil.
According to hydraulic principles, a pressure differential is established between the two sides of the puck, due to the presence of the radially disposed orifice restriction. The pressure differential is proportional to the lubricant density, the square of the flow velocity, inversely proportional to the fourth power of the effective ratio of the collective orifice diameter to the effective puck intake and outlet diameters, and inversely proportional to the square of an empirical operator known as the discharge coefficient. This equation and theory is based on Bernoulli""s equation and the net result of interest for the present invention is the presence of a pressure differential between the intake and outlet side, or the pump and filter side of the puck. Based on that observation, a sealed hollow chamber or duct is provided inside the puck. Multiple magnets, or other filter media, are placed inside the sealed chamber or duct. Next, diametrically opposed sets of control orifices, carefully sized with predetermined numbers and diameters, are made on the engine side or lubricant flow upstream side, and on the filter side or lubricant flow downstream side. The orifices in the upstream side and on the downstream side, effectively become the intake and exhaust of a self-contained magnetic bypass filter respectively. The puck is easily secured by means of a threaded nipple custom fitted from a few widely used thread sizes. An easily designed one-size-fit-all circular base gasket to seal the pump side of the puck to the engine is also provided.
Accordingly, there exists a need for removing magnetic particulate suspended in a fluid, particularly from internal combustion engines in order to reduce engine wear caused by abrasion of recirculating contaminants suspended in the lubricating fluid by using an apparatus which will remove the suspended contaminants, be simpler, less expensive, more space efficient, easily installed and maintained than prior art.
It is therefore, a primary object of the present invention to provide an apparatus that removes contaminants suspended in a lubricating fluid, and more particularly the removal of magnetic particulate from the lubricating fluid, which includes unappreciated advantages and unsuggested design modifications in prior art, that has all the advantages and additional complementary benefits from design advantages and has none of the unrecognized problems and undesirable design shortcomings found in prior art.
A further object of the present invention is to provide a filter apparatus, that slows down the lubricant flow to effect successful, continuous, consistent entrapment and retention of the suspended particles.
An additional object of the present invention is to provide a filter apparatus that exposes the lubricant flow directly to the magnet surface to avoid magnetic leakage and field weakening as is widely practiced in prior art.
Yet another object of the present invention is to provide a filter apparatus that controls the turbulence of the fluid to enhance particle capture and to minimize particle cluster separation.
A further object of the present invention is to provide a filter apparatus that maximizes poles and magnet surface utilization by exposing the surface and poles directly to the lubricant flow in order to minimize particle cluster separation by maximizing trapped volume capability while minimizing cluster thickness.
A still further object of the present invention is to provide a filter apparatus that maximizes magnet area exposed to maximize cluster retention volume, thereby maximizing or eliminating cleaning maintenance intervals.
Yet another object of the present invention is to provide a filter apparatus that utilizes the relatively abundant clearance provided in the longitudinal direction to facilitate installation in a cramped engine bay.
A further object of the present invention is to provide a filter apparatus that uses the dimension commonality of filter base diameters to facilitate a one-size-fit-all installation at lower cost.
A still further object of the present invention is to provide a filter apparatus that uses symmetry and enjoys design advantages to minimize labor and parts.
Yet another object of the present invention is to provide a filter apparatus that uses engine design common geometry to produce a product that can be installed in a few minutes without using special tools nor expensive and time consuming engine modifications.
A further object of the present invention is to provide a filter apparatus that minimizes parts and space utilization in an already cramped engine bay by providing a small single part and location device.
Another object of the present invention is to provide a filter apparatus that uses its own physical attributes to yield the additional function of cooling the filtered flow.
An even further object of the present invention is to provide a filter apparatus that is new and improved which is susceptible to low cost of manufacture with regard to labor and materials, and which accordingly is susceptible to low price to the buying public, thereby making the present invention economically available to the buying public.
In addition to the aforementioned objects the following advantages are found in the present invention over prior art. The present invention:
a. eliminates transferring the device from the used canister to the new canister;
b. eliminates the use of special high melting point material straps;
c. eliminates the risk of accidental detachment in high vibration environments;
d. eliminates magnetic leakage and makes full use of the magnetic field and area;
e. eliminates the need for special tools, skills, and modifications for its installation;
f. eliminates the risk of clogging the lubricant conduits;
g. eliminates the need to accommodate a great number of canister diameters;
h. eliminates special magnet amplification arrangements;
i. eliminates the problems associated with limited radial clearances;
j. eliminates the need of critical space in present cramped engine bays;
k. eliminates complicated and bulky external hardware;
l. eliminates the need to take the bypass lubricant volume from the main flow
m. eliminates the need to orient connections to a remote bypass filter
n. eliminates the use of metallic straps that short circuit the magnetic field
o. eliminates the possibility of magnet vibration shift and the resulting particle cluster separation.
p. eliminates more frequent cleaning by maximizing use of magnetic strength and available magnetic area.
Further objects of the invention will appear as the description proceeds and claims drawn. To the accomplishment of the above and related objects, this invention is embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims.